The use of biologically occurring redox centers holds a great potential in designing sustainable energy storage systems. Yet, to become practically feasible, it is critical to explore optimization strategies of biological redox compounds, along with in-depth studies regarding their underlying energy storage mechanisms. In this talk, a molecular simplification strategy combined with nano architecture is demonstrated to tailor the redox unit of pteridine derivatives in practical rechargeable batteries, which are essential components of ubiquitous electron transfer proteins in nature. It is applied to pteridine systems of alloxazinic structure in lithium/sodium rechargeable batteries, and their reversible tautomerism is unveiled during energy storage. Through the molecular tailoring, the pteridine electrodes can show outstanding performance, delivering 533 Wh kg-1 within 1 hour and 348 Wh kg-1 within 1 minute, as well as high cyclability retaining 96% of the initial capacity after 500 cycles at 10 A g-1. Our strategy combined with experimental and theoretical studies enriches the pool of sustainable energy materials and suggests guidance for the rational design for organic redox centers.